Erbman clutch slipping is a common problem across the board. The recommendation was from a major clutch manufacture. It's great that you are happy with what you have. But just so you know yamaha doesn't make oil neither does HD. I know HD guys that don't run synthetic. Plus HD doesn't cover the clutch plates period.
You did have problems with your clutch and added a Virago spring. Just so you know that actual decreases the amount of oil your clutch gets. These plates are not bathed in oil, it is merely splashed on it.
Last I would like to add into the theory that any clutch manufacture will say. Synthetic or not prolonged oil change interval potentiate the wear of clutch and debris in oil that goes to the engine.

Again glad it is working for you, but some of us have a problem and this is a free exchange.

OIl companies make products just like anyone of another industry. They create a designer product yet they didn't make it for our bike,car truck boat specific. Yes there are test and those test have + _ errors and top and bottom.
I did do a search and oil companies say no problem, forums like this had a mixed review. Many like you and just as many running dino due to slippage with synthetic.

part of the issue is shifting too soon or trying to get on the throttle in 2nd & 3rd at too slow a traveling speed.

if you drag it to the limit in each gear i bet it doesnt slip,much if any.

i have 2 stock oils in the shop here, 20/50 dino bel-ray, and 10/40 synth bel-ray (both bike specific), and castrol GPS 10/40 synth for some of my clients that run sports bikes.

to date, (after 6 years of using these oils) no problems with slippage on any of the bikes using the synth.

occasionally i have to change a clutch, but this is purely down to wear and tear.

i did have some slippage issues at one point, but this was after i mounted various go-faster goodies and it got to the point that the clutch (which on our roadies is a bit of a weak link when upping the ponies) started to slip a bit. fitted a warrior diaphragm and has been great ever since.

funnily enough, yesterday i had the opportunity to drag my oils over the coals as someone bought in a piece of equipment that tests wear qualities in a manner similar to ASTM D-4172.

the wear results were interesting. the bel-ray 10/40 came out on top, and the 20/50 dino and the GPS synth came out about the same with little if any difference.

i personally run the 20/50 dino in mine. with temps hitting 45ºc here in the summer and some serious traffic conditions, she seems to like it without getting `clattery´ when riding in high temps in heavy slow traffic.

Some of you may not know this, but some oils have friction modifiers in them! Look on the little circle on the side of the oil container, and if the bottom of the circle says energy conserving, it has them.. which in turn will cause clutch slippage... Most oils above 10-30 do not have modifiers....10-40, 10-50, so on and so forth...synthetic or dino, all the same...........Never put additives such as Slick 50 or Duralube, in a wet clutch or you will be replacing it!! Hope this helps.... Butch

Agpilot wrote:
Never put additives such as Slick 50 or Duralube, in a wet clutch or you will be replacing it!! Hope this helps.... Butch

as it goes, slick 50 does an additive specifically for bikes with wet clutches (not to be confused with their normal car treatment).

had a client who insisted i add it in an oil change, and 30,000 miles later it´s still going fine with no slippage.

As far as Duralube, I know lots and lots of riders that always add Duralube to their oil and none of them have clutch problems from it. I run the Mobile V- Twin syn. and last oil change I added the Duralube to try it out. Both seem to run fine. I think riding expertise and style have more to do with cluth wear and slippage than anything, as long as you are not running oil with 'energy saving' additives.

Erbman02 wrote:
well, if no clutch was meant to use syn, then why do new HD's come with it from factory. what a crock. then also why then does so many MC oil makers make full syn?

I've been running syn since 1k miles and auto oil to boot, now at 112k and I have zero clutch slippage.

shoot, I'd have to do 8 oil changes a yr if I run dino, that just ain't gonna happen


Harleys don't use engine oil to lube the trans/clutch. It's separate oil. Are you sure Harley uses synthetic in the transmission as well as the engine?

That is a big debate over in the HD forums. Alot of guys run the same oil in all 3 holes (engine, trans, and primary). I tried the synthetic 20W/50 in my Softail trans and didn't care for the way it felt. When I checked the level it was real foamed up so I went back to regular trans/gear lube and it felt and looked better. Amsoil claims you can run there synthetic engine oil in all 3 holes and I know alot of guys that have been running that way for a long time. It simplifies fluid changes just having to buy one type of fluid. I go by the feel and look of the fluid vs. convenience. Some HD stores will recommend their HD3 semi-synthetic in all 3 holes - but of course they are trying to move their product.

I posted this thread thinking people are up on things. All of a sudden I am crucified for using the word no, and accused of not knowing how to ride a bike after 40 years of riding, (Ok knock off two for having an auto clutch on a Honda 70) 38. I was just posting a cure to a common problem. If your clutch slips, and you have nothing to lose, it's worth a try. Put it in and take it out. Here is some info from someone who is way more knowledgeable than any of us, If you know more, post a link to your article.

Synthetics and Slipperiness in Relation to Roller Rockers and Wet Clutches
As a side note, we have received many reports of motorcycle shops telling customers that synthetic oil is so slippery that is causes roller bearings not to roll and will result in flat spots on the roller bearings. This is absolutely not true. Synthetic oil is no more “slippery” than petroleum oil. Synthetic oil is more uniform in molecular structure than a petroleum oil but it is not more slippery and will certainly not cause roller bearings to roll. Roller bearings will roll whether they are using petroleum oil or synthetic oil and the only way the roller bearing on the rocker arm will ever stop rolling is if the needle bearings that support the roller bearing failed. Every automotive racing engine (as well as many other types of high performance engines) and most of today’s high performance automobile engines use camshafts with sophisticated roller rockers with absolutely no problems of this nature whatsoever.

We have also received reports of motorcycle shops telling customers that synthetics are so “slippery” as compared to petroleum oils (which simply do not reduce friction as well) that wet clutch packs in their motorcycle transmission and even their automatic transmission of their cars and trucks will slip when using “slippery synthetics” even if there are no friction modifiers present. This is absolutely not true.

Look at it this way. Wet sandpaper removes paint as well as dry sandpaper does. The slipperiness of the water does not impede the sandpaper's ability to function. The same applies to the slipperiness of synthetic lubes in wet clutches. It is simply not an issue. However, just as rinsing the sandpaper keeps it cleaner longer so it functions better longer, so the synthetic lubricant keeps wet clutch plates cleaner longer so they function better. And, since synthetics are superior cooling agents to conventional petroleum lubes, using synthetics will help wet clutches last longer, too.

Petroleum oils have low resistance to heat and allow varnish and glaze to form on clutch plates, which can lead to slippage and increased heat generation and potential failure of the clutch pack. Synthetic oil is going to allow your wet clutches to perform better (especially under extreme heat, RPM and load conditions) and last longer than they would with petroleum oil subjected to the same operational conditions.

As a side note in respect to Automatic Transmission Fluid: synthetic ATF is not more “slippery” than petroleum ATF. The base fluids, whether or not petroleum oil or synthetic oil, play no direct role in the relative friction levels of wet clutches. The friction-modifying additives developed for petroleum oils work just as expected in synthetic PAO’s fluids. The longer the fluid resists oxidation, the longer the original frictional properties remain. The superior oxidative stability demonstrated for synthetic ATF’s thereby leads to extended retention of frictional properties.



Read more: http://www.smartsynthetics.com/articles/motorcycle_oil_technical_facts.htm#ixzz0hsHNWoLV
Info found here: http://www.smartsynthetics.com/articles/motorcycle_oil_technical_facts.htm

He said none of these, I said NO, Sorry. All I know about oil, I run synthetic Amsoil is my preference, I use Mobile V Twin when I am broke.

I posted a cure for a common problem, I'm sorry.

Edit link: http://en.wikipedia.org/wiki/Motorcycle_oil

I have more miles pushing my bike out of the shop backwards than a lot of you guys do riding forward!
Now how much trouble will that get me into!

Can someone post a link on how I don't know how to use a clutch, ride a bike, work on one? I had the balls to put seafoam in when no one else did. It cured my problem, It will come out today for a spell if it's cured totally, I'll add no more and go back to synthetic. Lead follow or get the hell out of the way!

Did I miss something MS I didn't take it as anyone "crucifying" you. Just a few opinions on the ever so beat to death synthetic oil debate. I say just like whatever bike you choose to ride, if you want to use synthetic oil then use it. I think the majority of people "read somewhere" that synthetic will make your clutch slip and have never actually went through the process to try it out. Alot of that is to blame on these powersports stores and them hiring uneducated parts and service guys that speak out of their ass to customers and now that customer is misinformed and repeats that misinformation to others.
I am not sure if you were referring to my comment here or not, but I was just stating personal experience which really had nothing to do with synthetic vs dino but more of running motor oil in a trans like alot of HD guys do. I personally felt better with the heavier gear lube in the trans vs. engine oil.
I appreciate the tip on the seafoam that is something I never thought about putting in the transfer case. Thanks!

P.S. Just cause you haven't figured out how to use a clutch yet you don't have to be embarrassed.